Step 1.
Open the Mail Program
Click "Mail" then "Preferences"
Step 2.
Choose "Create Account"
Step 3.
Choose "POP Account"
Type in your "Email Address"
Type in your "Full Name" (or your name as you wish it to appear on your emails)
Type in mail.<the end of your email address> for the "Host name". In the example above, you would type in mail.donobi.net since the email address is username@donobi.net.
Type in your "User name" if it isn't already filled in.
Type in your "Password"
Type in mail.<the end of your email address> for the "SMTP Host". In the example above, you would type in mail.donobi.net since the email address is username@donobi.net.
Check "Use authentication when sending mail"